1. Field
This invention relates to lawn mowers, and, more particularly, to lawn mowers having adjustable air vents for improved circulation within the cutting deck.
2. Description of the Prior Art
Lawn mowers, comprising a cutting deck having one or more blades disposed therein and an engine operatively connected to the blades, have been used for many years in the practice of lawn maintenance. Traditionally, both walk behind and riding mowers employ one or more rotating blades to cut the grass and discharge the clippings through a chute in the cutting deck, either outwardly onto the lawn or into a bag or similar receptacle for collection and subsequent disposal. It is well know that a certain degree of airflow through the cutting deck is essential for the effective discharge of grass clippings.
In more recent years, ecological advocates have discouraged the practice of disposing of grass clippings in landfills and the use of chemical fertilizers, and have encouraged the use of mulching mowers which return the pulverized grass clippings onto the ground to be used as natural organic fertilizer. It has become recognized that airflow within the cutting deck significantly affects the performance of a mulching mower. It has also been recognized that the airflow requirements for optimal mulching are different from the airflow requirement for discharging and/or bagging the clippings.
Initially, lawn mowers were designed to be used exclusively for either mulching or discharging grass clippings. It has recently been discovered that, by utilizing specially configured blades and cutting decks, a single mower may be adapted to either mulch or discharge, and to perform either function acceptably well. Numerous improvements have been made in the design of blades, cutting decks, and plugs for sealing the discharge chute, all of which have improved both the mulching and discharging characteristics of various lawn mowers. The varying airflow requirements for such multi-purpose lawn mowers have largely been ignored in the prior art.
It has also been observed that the height and moisture content of grass being cut significantly affect the airflow requirements, regardless of whether the grass clippings are to be discharged or mulched. Heretofore, little attention has been paid to the airflow needs through a cutting deck which vary considerably depending upon the condition of the grass and the disposition of the clippings.